#Really Weird Problem
9 messages in this thread
I have an A500 with a dead DF0:. Recently I can no longer activate icons on the
desktop without the whole system freezing. Any ideas? Programs run fine from
menus and docks etc.
Sounds like a toasted CIA chip, but maybe someone else has a better idea.
Mr. Zombie
I agree, I've seen a toasted cia chip cause those same symptoms. Best
thing to do is swap the two chips & see if the bugs change.
-Jim
MOS via Autopilot & Amiga
What does the cia chip look like? What does it do?
It overthrows small foreign governments, and for all practical purposes it's
invisible.
Mr. Zombie
Peter,
the CIA chips bear the number 8520, there's a pair of them in your Amiga which
is (as far as I remember) located to the rear center of your A500. On the
motherboard there should 'even' and 'odd' and/or 'CIA-A' and 'CIA-B' be written
beside or in front of the chips so you know which is which. The CIA chips are
used for a whole lot of things in the Amiga so in quite a lot of cases when it
acts weird, a 'fried' CIA is to blame. As there are two of them you can easily
swap them and see if your problems disappear (and others appear in their place,
due to the other CIA chip now being the defective one…). I don't know what
they really do – there are some timers integrated in the CIAs, and they have
some function or other with the ports (Serial, Parallel and floppy). Other than
that I have no idea. But you can see they're pretty vital to your Amiga's
operation. Unfortunately though they seem to be in no way protected from harm –
you can fry a CIA by just plugging/unplugging a cable (serial, parallel) with
your Amiga powered on (which is why you should never do that according to the
books…)
Cheers,
// Christian "ELP" Busse
\X/ near Frankfurt, Germany
Thanks. Now I just have to find a supplier in OZ that still stocks parts.
I'd swap 'em before buying new chips, although in these times, having a
spare set makes sense. In any case, based on your description, I'd say
that if you swapped them, the printer would stop working properly.
-Jim
MOS via Autopilot & Amiga
Christian,
I had a real "Twilight Zone" failure on my 1000 with a bad 8520. The
time of day clock kept repeating the same 1:27 over and over. It was
actually useful for some games. They appeared to set their initial
conditions based on the 8520's counter. The bad chip only allowed maybe
half a dozen configurations in Hack…. once you recognized the layout,
you knew where all the treasures were hidden. 🙂
-Jim
MOS via Autopilot & Amiga